Past meetings of the Society
February 2008

February 2008 Meeting

Date: Sunday, February 17, 2008
Time: 6:00 PM
Place: Boston University, Life Science & Engineering Bldg, 24 Cummington St, 1st Floor Conference Room (room 103), Boston, MA 02215, (617) 271-6588

Featured Guest: Joseph DeMarinis, Winchester Lab

Topic: Techniques for Speaker Measurements

The BAS talk will consist of a PowerPoint presentation using a DLP projector. It will give a photographic overview of my lab and the equipment, describe the measurement techniques and show some of the test results.

Part 2 will explain some of the techniques & limitations of converting an audio signal into a spectrum display, using a Fast Fourier Transform (FFT). I will compare results from Pulse and White Noise sources. I will also discuss how using a pulse window can eliminate room reflections from a measurement, and the limitations of that technique.

For Part 3, I have two "Live" Excel macro demonstrations of the inner mechanism of how a Fourier Transform works. It is an attempt to show, in a simple and visual way, something that is generally poorly understood.

Born and raised in New York City, I graduated 1956 from Manhattan College with a degree in Electrical Engineering. While in college, I earned money by running my own TV repair business. For the next 25 years I worked for the Consumer Electronics Division of Sylvania in Batavia, NY, starting as a TV design engineer and ending as Chief Engineer of the Division. During part of that tenure I was manager of Audio Engineering. Audio has always been an intense interest, since the days that the word "HiFi" was first coined. Amateur Radio was also an intense interest in those days.

When Sylvania collapsed, I joined Sylvania's parent company, GTE, moved to Boston and worked closely with GTE Labs on a project to investigate the prospects of Home Terminals as part of the telephone business. That project was short-lived and I joined Digital Equipment Corporation as a senior manager in the small systems group, where I worked on Terminals and Personal Computers. Part of that was to help DEC get set up with measurement sites & the skills necessary to comply with the "new" FCC RF emissions regulations. One result of the research I did there, was to publish several papers in the IEEE journal on Electromagnetic Compatibility. That got me a seat on the IEEE EMC Standards Committee.

DEC eventually collapsed and I went to Polaroid as a senior manager in their Digital Imaging group. There, I worked on digital cameras and a variety of high-resolution digital film printers. At that time our Country's HDTV system was being developed and I was granted a seat on the IEEE Consumer Electronics committee on standards & testing. I participated as an "expert observer" in some of that testing in the Washington DC area. At Polaroid I had my own lab, equipped for Colorimetry, CRT technology, optics, FCC compliance and other technologies.

Eventually Polaroid too, collapsed. By then I was well past the normal retirement age and retired. But before leaving, I was able to buy most of the equipment in my lab at essentially scrap prices. That gave birth to on the third floor of my home. Most of what I do there is audio measurements on microphones & speakers and whatever puttering arouses my interest.

Having worked for three companies that failed, I doubt that anyone would want to hire me now!


The Boston Audio Society
PO BOX 260211
Boston MA 02126

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updated 3/27/08